The term was first used in 1776 by the physician W Cullen. In contemporary usage, neuroses include only disorders arising from psychic traumas and prolonged nervous tension. The predisposing factors are bodily constitution and trauma, intoxication, infection, and other debilitating diseases. Neurosis may be caused by an overpowering acute psychic trauma, such as the sudden loss of a loved one. Persistent psychic traumas, especially if they give rise to internal conflicts, may also result in neurosis. Overstrain of the nervous system is the basis for neuroses and this is more likely to occur in persons whose nervous systems are weak, imbalanced, or insufficiently responsive. Neurotic people are easily fatigued, easy excited, suffer rapid exhaustion, disturbed sleep habits, sweating, and unpleasant sensations in the chest near the heart.